Officials are investigating a suspicious fire at a vacant apartment building in Saint John’s old north end.

Fire crews were called to the six-unit building on Metcalfe Street shortly after 6 a.m. Wednesday.

Firefighters spent most of Wednesday morning battling the blaze. They say flames were burning through the roof and hidden in the walls and it was challenging to bring them under control.

“It will travel freely on the inside of those walls and that’s a challenge in any of these buildings,” said Saint John Fire Chief Kevin Clifford. “It’s called balloon-frame construction, so it’s very dangerous.”

Thick smoke from the fire spread throughout the neighbourhood and adjacent buildings were evacuated as a precaution.

Clifford says the fire is suspicious in nature and an investigation is underway.

Meanwhile, neighbours say there are too many vacant buildings in the area, and that suspicious fires are becoming all too common.

“There’s a ton of them around here. They really should be torn down, I think, just from history repeating itself, and all these fires,” said area resident Shannon Caldwell.

“We’ve had a few fires around here in the last year or two, and it would be nice if the city did something about it,” said neighbour Barry Harris. “Probably a matter of time before someone gets hurt.”

Others point out that, in addition to being dangerous, the fires are costly and tie up resources.

“The equipment and the resources that it’s tying up and the cost, you know, they gotta do something,” said resident Brian Lang. “There’s got to be a law somewhere that they can get rid of these buildings.”

Clifford says there are a number of buildings of concern and that repairing them or tearing them down is a work in progress.

“Our growth and community development folks are doing a lot of good work around either getting buildings improved or actually through the process of having them torn down,” he said.

No one was injured.

With files from CTV Atlantic's Mike Cameron